Abstract: A base material for a hard sintered material has a multi-stage columnar shape having a central axis and extending in an axial direction of the central axis. The base material includes a smaller-diameter portion, a larger-diameter portion, a base material end surface located between a one end portion in the axial direction of an outer peripheral surface of the larger-diameter portion and the other end portion in the axial direction of the smaller-diameter portion, and facing toward the one end portion in the axial direction, and a first inclined portion disposed in at least a portion in a circumferential direction of an annular corner portion to which an outer peripheral surface of the larger-diameter portion and the base material end surface are connected. The first inclined portion is located inward in a radial direction toward the one end portion in the axial direction.

Abstract: A base material for a hard sintered body includes a pillar portion having a central axis and extending in the axial direction of the central axis. The pillar portion has a first outer peripheral portion, a second outer peripheral portion, and a protruding stripe portion. In the cross-sectional view, one side portion of the first outer peripheral portion extending in a circumferential direction or a radial direction is located inside the other side portion. In the cross-sectional view, one side portion of the second outer peripheral portion extending in the circumferential direction or the radial direction is located outside the other side portion in the radial direction. The protruding stripe portion is located in a connection portion between the other side portion of the first outer peripheral portion and one side portion of the second outer peripheral portion, and protrudes outward.

Abstract: In a roughing end mill, an end mill main body is provided with: a peripheral cutting edge; an end cutting edge; and a corner cutting edge formed between the peripheral cutting edge and the end cutting edge. A roughing part having a waveform pattern of recesses and protrusions is formed in the peripheral cutting edge, and a phase of the recesses and protrusions of the roughing part of one chip discharge flute is shifted with respect to that of the other chip discharge flute adjacent to the one chip discharge flute. A foremost protrusion of the roughing part of one peripheral cutting edge is located closer to a distal end of the end mill main body than those of the other peripheral cutting edges, a peak of the foremost protrusion of the one peripheral cutting edge is aligned with another peak of the corner cutting edge adjacent to the one peripheral cutting edge.

Abstract: An end mill body comprises: bottom blades formed at ridgelines where gashes and tip flank faces intersect, the gashes are formed at the tips of chip discharge grooves. At least one of the bottom blades serves as a long bottom blade that extends toward an inner peripheral side longer than the remaining bottom blades. The end mill body also has coolant holes formed between the chip discharge grooves. A coolant hole which is located between a chip discharge groove of a gash and a chip discharge groove located behind the chip discharge groove in a rotational direction is open to the tip clearance face of the long bottom blade. A coolant hole which is located between the chip discharge groove of the gash and a chip discharge groove located in front of the chip discharge groove in the rotational direction is open to the gash of the long bottom blade.

Abstract: Disclosed is a radius end mill equipped with end cutting edges formed such that rotational locus thereof around an axial line draw a protruded curved face. That is, the protruded curved face is formed so as to have a protruded curved face where a curvature radius in an inner portion located closer to an axial line side than a tip outer-peripheral side of an end mill body is greater than a curvature radius on the tip outer-peripheral side, in a sectional view along the axial line. A gash depth angle ?(°) calculated by ?=tan?1 (A/B) on the basis of a distance A in an axial direction from a protruded end of an end cutting edge to a most-posterior end of a gash and a radius B from the axial line to a contact point between a peripheral cutting edge and the end cutting edge is set to be 50° or less.

Abstract: Even if chips enter a gap between a flank face and a surface to be worked, the defect of the flank face or a cutting edge is suppressed by the control of the flow of the chips. A plurality of cutting edges, which are undulated in wave forms in a direction of an axis, are formed on an outer periphery of a front end portion of an end mill body rotating about the axis so that phases of the wave forms are displaced from each other in a path of rotation about the axis; flank faces of the cutting edges are covered with a coating film; and rough surface regions and smooth surface regions are alternately formed on the surface of at least portions of the coating film, which are close to the cutting edges, in the direction of the axis.

Abstract: In a roughing end mill, an end mill main body is provided with: a peripheral cutting edge; an end cutting edge; and a corner cutting edge formed between the peripheral cutting edge and the end cutting edge. A roughing part having a waveform pattern of recesses and protrusions is formed in the peripheral cutting edge, and a phase of the recesses and protrusions of the roughing part of one chip discharge flute is shifted with respect to that of the other chip discharge flute adjacent to the one chip discharge flute. A foremost protrusion of the roughing part of one peripheral cutting edge is located closer to a distal end of the end mill main body than those of the other peripheral cutting edges, a peak of the foremost protrusion of the one peripheral cutting edge is aligned with another peak of the corner cutting edge adjacent to the one peripheral cutting edge.

Abstract: The discharge performance of chips generated by end cutting edges adjacent to a backward side of a long end cutting edge in a rotational direction of an end mill is improved. End cutting edges are formed at intersecting ridgeline portions between tip flank faces and gashes at the tips of a plurality of chip discharge grooves that are formed in an end mill body. At least one of the end cutting edges is a long end cutting edge that extends further toward an inner peripheral side than the other end cutting edges. Coolant holes are formed between the chip discharge grooves within the end mill body.

Abstract: Even if chips enter a gap between a flank face and a surface to be worked, the defect of the flank face or a cutting edge is suppressed by the control of the flow of the chips. A plurality of cutting edges, which are undulated in wave forms in a direction of an axis, are formed on an outer periphery of a front end portion of an end mill body rotating about the axis so that phases of the wave forms are displaced from each other in a path of rotation about the axis; flank faces of the cutting edges are covered with a coating film; and rough surface regions and smooth surface regions are alternately formed on the surface of at least portions of the coating film, which are close to the cutting edges, in the direction of the axis.

Abstract: An end mill body comprises: bottom blades formed at ridgelines where gashes and tip flank faces intersect, the gashes are formed at the tips of chip discharge grooves. At least one of the bottom blades serves as a long bottom blade that extends toward an inner peripheral side longer than the remaining bottom blades. The end mill body also has coolant holes formed between the chip discharge grooves. A coolant hole which is located between a chip discharge groove of a gash and a chip discharge groove located behind the chip discharge groove in a rotational direction is open to the tip clearance face of the long bottom blade. A coolant hole which is located between the chip discharge groove of the gash and a chip discharge groove located in front of the chip discharge groove in the rotational direction is open to the gash of the long bottom blade.